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Cmos Battery/Clock

Started by amdx December 1, 2014
Well I've received my M48T86PC1 Cmos Clock Lithium Battery as a gift 
from China, according to the custom declaration.
  It is an ST microelectronics part, my concern is the manufacturing date.
  The Chip is labeled as below,

            M48T86PC1
            Real-Time Clock
           Contains Lithium Cell
           990SN  VH
           MYS  99    1033
              WO723Y

I hate seeing all the 99's, any one know how to read a date code
for ST microelectronics.

Another route, any chance I could measure the battery voltage?
The pinout is here but I don't know if the battery voltage is present on 
any pin.
http://www.datasheetarchive.com/dlmain/Datasheets-31/DSA-600395.pdf

  I wish I would have done a little more research before ordering this 
chip, I'm now finding a replacement chip DS12887. With chips available 
from Mouser and Digikey, so I expect recent manufacture.

  Maybe I'll be lucky and this chip will be found to be recent manufacture.
  I only want to replace the chip once on the motherboard, a second time
might be pressing my luck. I'll order a second newer chip if it seems 
appropriate.

                        Your help appreciated, Mikek

On 12/1/2014 6:51 PM, amdx wrote:
> Well I've received my M48T86PC1 Cmos Clock Lithium Battery as a gift > from China, according to the custom declaration. > It is an ST microelectronics part, my concern is the manufacturing date. > The Chip is labeled as below, > > M48T86PC1 > Real-Time Clock > Contains Lithium Cell > 990SN VH > MYS 99 1033 > WO723Y > > I hate seeing all the 99's, any one know how to read a date code > for ST microelectronics. > > Another route, any chance I could measure the battery voltage? > The pinout is here but I don't know if the battery voltage is present on > any pin. > http://www.datasheetarchive.com/dlmain/Datasheets-31/DSA-600395.pdf > > I wish I would have done a little more research before ordering this > chip, I'm now finding a replacement chip DS12887. With chips available > from Mouser and Digikey, so I expect recent manufacture. > > Maybe I'll be lucky and this chip will be found to be recent manufacture. > I only want to replace the chip once on the motherboard, a second time > might be pressing my luck. I'll order a second newer chip if it seems > appropriate. > > Your help appreciated, Mikek >
I measured 0.0V between pin 12 and pin 24. FWIW. Mikek
On 12/1/2014 6:51 PM, amdx wrote:
> Well I've received my M48T86PC1 Cmos Clock Lithium Battery as a gift > from China, according to the custom declaration. > It is an ST microelectronics part, my concern is the manufacturing date. > The Chip is labeled as below, > > M48T86PC1 > Real-Time Clock > Contains Lithium Cell > 990SN VH > MYS 99 1033 > WO723Y > > I hate seeing all the 99's, any one know how to read a date code > for ST microelectronics. > > Another route, any chance I could measure the battery voltage? > The pinout is here but I don't know if the battery voltage is present on > any pin. > http://www.datasheetarchive.com/dlmain/Datasheets-31/DSA-600395.pdf > > I wish I would have done a little more research before ordering this > chip, I'm now finding a replacement chip DS12887. With chips available > from Mouser and Digikey, so I expect recent manufacture. > > Maybe I'll be lucky and this chip will be found to be recent manufacture. > I only want to replace the chip once on the motherboard, a second time > might be pressing my luck. I'll order a second newer chip if it seems > appropriate. > > Your help appreciated, Mikek >
Argh, I think I've found it. Above I listed the WO723Y. This is sideways on the end of the chip. I see here on this application note, application-notes.digchip.com/005/5-9794.pdf "The 6-character encapsulation code (CAPHAT� only; Figure 6) is positioned at the end of the device and is placed perpendicularly to the date code. It summarizes details of the encapsulation process" It tells me, it was manufactured on the 72nd day of 2003. Anyone looking at the application note disagree with my conclusion? Thanks, Mikek
"amdx" <nojunk@knology.net> wrote in message 
news:m5j31c$g0a$1@dont-email.me...
> On 12/1/2014 6:51 PM, amdx wrote: >> Well I've received my M48T86PC1 Cmos Clock Lithium Battery as a gift >> from China, according to the custom declaration. >> It is an ST microelectronics part, my concern is the manufacturing >> date. >> The Chip is labeled as below, >> >> M48T86PC1 >> Real-Time Clock >> Contains Lithium Cell >> 990SN VH >> MYS 99 1033 >> WO723Y >> >> I hate seeing all the 99's, any one know how to read a date code >> for ST microelectronics. >> >> Another route, any chance I could measure the battery voltage? >> The pinout is here but I don't know if the battery voltage is present on >> any pin. >> http://www.datasheetarchive.com/dlmain/Datasheets-31/DSA-600395.pdf >> >> I wish I would have done a little more research before ordering this >> chip, I'm now finding a replacement chip DS12887. With chips available >> from Mouser and Digikey, so I expect recent manufacture. >> >> Maybe I'll be lucky and this chip will be found to be recent >> manufacture. >> I only want to replace the chip once on the motherboard, a second time >> might be pressing my luck. I'll order a second newer chip if it seems >> appropriate. >> >> Your help appreciated, Mikek >> > > I measured 0.0V between pin 12 and pin 24. FWIW. > Mikek
I would say it is the 33rd week of 2010. You will not be able to measure the battery, there is an isolation diode (actually a power management chip) that kills the chip select line when Vcc drops below 4.5 volts. Also, you might wish to install a good quality machined pin socket to make the next change easier.
On 12/1/2014 7:24 PM, Tom Miller wrote:
> > "amdx" <nojunk@knology.net> wrote in message > news:m5j31c$g0a$1@dont-email.me... >> On 12/1/2014 6:51 PM, amdx wrote: >>> Well I've received my M48T86PC1 Cmos Clock Lithium Battery as a gift >>> from China, according to the custom declaration. >>> It is an ST microelectronics part, my concern is the manufacturing >>> date. >>> The Chip is labeled as below, >>> >>> M48T86PC1 >>> Real-Time Clock >>> Contains Lithium Cell >>> 990SN VH >>> MYS 99 1033 >>> WO723Y >>> >>> I hate seeing all the 99's, any one know how to read a date code >>> for ST microelectronics. >>> >>> Another route, any chance I could measure the battery voltage? >>> The pinout is here but I don't know if the battery voltage is present on >>> any pin. >>> http://www.datasheetarchive.com/dlmain/Datasheets-31/DSA-600395.pdf >>> >>> I wish I would have done a little more research before ordering this >>> chip, I'm now finding a replacement chip DS12887. With chips available >>> from Mouser and Digikey, so I expect recent manufacture. >>> >>> Maybe I'll be lucky and this chip will be found to be recent >>> manufacture. >>> I only want to replace the chip once on the motherboard, a second time >>> might be pressing my luck. I'll order a second newer chip if it seems >>> appropriate. >>> >>> Your help appreciated, Mikek >>> >> >> I measured 0.0V between pin 12 and pin 24. FWIW. >> Mikek > > I would say it is the 33rd week of 2010.
Does my followup with the application note change your mind? application-notes.digchip.com/005/5-9794.pdf I think the manufacture date is 72nd day of 2003. Mikek
On 12/1/2014 8:18 PM, amdx wrote:
> On 12/1/2014 6:51 PM, amdx wrote: >> Well I've received my M48T86PC1 Cmos Clock Lithium Battery as a gift >> from China, according to the custom declaration. >> It is an ST microelectronics part, my concern is the manufacturing >> date. >> The Chip is labeled as below, >> >> M48T86PC1 >> Real-Time Clock >> Contains Lithium Cell >> 990SN VH >> MYS 99 1033 >> WO723Y >> >> I hate seeing all the 99's, any one know how to read a date code >> for ST microelectronics. >> >> Another route, any chance I could measure the battery voltage? >> The pinout is here but I don't know if the battery voltage is present on >> any pin. >> http://www.datasheetarchive.com/dlmain/Datasheets-31/DSA-600395.pdf >> >> I wish I would have done a little more research before ordering this >> chip, I'm now finding a replacement chip DS12887. With chips available >> from Mouser and Digikey, so I expect recent manufacture. >> >> Maybe I'll be lucky and this chip will be found to be recent >> manufacture. >> I only want to replace the chip once on the motherboard, a second time >> might be pressing my luck. I'll order a second newer chip if it seems >> appropriate. >> >> Your help appreciated, Mikek >> > > Argh, I think I've found it. Above I listed the WO723Y. This is sideways > on the end of the chip. I see here on this application note, > application-notes.digchip.com/005/5-9794.pdf > "The 6-character encapsulation code (CAPHAT&#4294967295; only; Figure 6) is > positioned at the end of the device and is placed perpendicularly to the > date code. It summarizes details of the encapsulation process" > It tells me, it was manufactured on the 72nd day of 2003. > Anyone looking at the application note disagree with my conclusion? > > Thanks, Mikek
One point, the year is a single digit and 2003 is over 10 years old. That is near if not past the end of its shelf life. I'd say it is more likely the date is 2013 and the app note is out of date, but who can say? One the other hand, why couldn't this be a 24 pin CAPHAT in figure 5? All the lettering makes sense and it then has a date code of 2010, 33rd work week, much preferable over 2003 (I'm assuming they added a year digit in 2010). Maybe Fig 5 is the date of manufacture of the chip and the 2013 encapsulation code is the date when it was all potted? -- Rick
On 2014-12-02, amdx <nojunk@knology.net> wrote:

> Another route, any chance I could measure the battery voltage?
Absolutely, I told you how last month. -- umop apisdn
Am 02.12.2014 um 06:53 schrieb Jasen Betts:
> On 2014-12-02, amdx <nojunk@knology.net> wrote: > >> Another route, any chance I could measure the battery voltage? > > Absolutely, I told you how last month. >
Oh, please let us knew how, too! tnx Jorgen
On 12/1/2014 11:53 PM, Jasen Betts wrote:
> On 2014-12-02, amdx <nojunk@knology.net> wrote: > >> Another route, any chance I could measure the battery voltage? > > Absolutely, I told you how last month. >
You said, "It's a regular 0.3" PDIP CMOS RTC chip potted with a lithium battery, they can be opened and the chip connected to a replacable battery." I tore up as much of the cover as I could and have not got to the battery. It is fitted between two PCI connectors with very little room to maneuver. I'm not going to tear up this maybe new? 2003 or 2013 chip just to measure the battery. Thanks, Mikek
On 12/1/2014 7:24 PM, Tom Miller wrote:
> > "amdx" <nojunk@knology.net> wrote in message > news:m5j31c$g0a$1@dont-email.me... >> On 12/1/2014 6:51 PM, amdx wrote: >>> Well I've received my M48T86PC1 Cmos Clock Lithium Battery as a gift >>> from China, according to the custom declaration. >>> It is an ST microelectronics part, my concern is the manufacturing >>> date. >>> The Chip is labeled as below, >>> >>> M48T86PC1 >>> Real-Time Clock >>> Contains Lithium Cell >>> 990SN VH >>> MYS 99 1033 >>> WO723Y >>> >>> I hate seeing all the 99's, any one know how to read a date code >>> for ST microelectronics. >>> >>> Another route, any chance I could measure the battery voltage? >>> The pinout is here but I don't know if the battery voltage is present on >>> any pin. >>> http://www.datasheetarchive.com/dlmain/Datasheets-31/DSA-600395.pdf >>> >>> I wish I would have done a little more research before ordering this >>> chip, I'm now finding a replacement chip DS12887. With chips available >>> from Mouser and Digikey, so I expect recent manufacture. >>> >>> Maybe I'll be lucky and this chip will be found to be recent >>> manufacture. >>> I only want to replace the chip once on the motherboard, a second time >>> might be pressing my luck. I'll order a second newer chip if it seems >>> appropriate. >>> >>> Your help appreciated, Mikek >>> >> >> I measured 0.0V between pin 12 and pin 24. FWIW. >> Mikek > > I would say it is the 33rd week of 2010. > > You will not be able to measure the battery, there is an isolation diode > (actually a power management chip) that kills the chip select line when > Vcc drops below 4.5 volts. > > Also, you might wish to install a good quality machined pin socket to > make the next change easier. > >
On third thought, your Date works and makes more sense. MYS 99 1033 MYS = Malaysia 99 = Tested in Muar 1033 the 10 = 2010, 33 = 33rd week Where it says, "The 6-character encapsulation code (CAPHAT&#4294967295; only; Figure 6) is positioned at the end of the device and is placed perpendicularly to the date code. It summarizes details of the encapsulation process" Yep, perpendicular to the date code is WO723Y which as it says, "summarizes details of the encapsulation process" I now feel comfortable with installing this chip. Tom, thanks, for your input and forcing me to think, although I thought I did think, but I needed to think some more. Next question, Why is anyone making this chip anymore? Does anyone still use this on a mother board? Where else might it be used.